1. Field of Invention
This invention relates generally to a hula-hoop, and more particularly to a collapsible hoop of this type formed by an inflatable core enclosed within a fabric casing.
2. Status of Prior Art
A hula is a Polynesian dance characterized by undulating hips. The hula dance may have inspired the Hula-Hoop, the trademark for a light-weight plastic ring which is whirled around the body of a player for play or exercise by movement of the hips.
A hula-hoop plastic ring has a relatively large diameter and since its form is fixed, it has certain practical drawbacks. Thus if a child wishes to take both a ball and a hula-hoop to a park or playground, he may have difficulty in doing so. Should the ball be inflatable, it can be collapsed and carried in the child's backpack. But a conventional hula-hoop cannot be collapsed, and its diameter is such that it is awkward for a child or even an adult to carry. Moreover, a hula-hoop, when sold in a toy store, takes an inordinate amount of space, for it cannot be collapsed to fit into a relatively small box.
Of prior art interest is U.S. Pat. No. 4,384,382 to Spector which discloses a pneumatic playball that has the configuration and appearance of a standard pneumatic athletic ball, such as a regulation basketball.
The Spector ball is constituted by an inner inflatable balloon confined within a fabric outer casing. The outer casing is formed by contoured segments of high strength, non-stretchable fabric material stitched together to create, when the casing is fully expanded, a play ball of the desired shape and size, such as a football or soccer ball. The balloon is a conventional thin-skin rubber balloon whose stem initially projects through a slit in the fabric casing. After inflating the balloon with air so that it conforms to the casing, the stem is then tied into a knot to seal the balloon, and the tied stem is pushed into the casing under the slit.
An unconfined rubber balloon has little strength and is easily burst. But when the same balloon is inflated within the confines of a non-stretchable fabric casing, even though the balloon, per se, is inherently weak, the casing does not permit any region of the balloon to further expand beyond its existing degree of expansion; hence the balloon will not burst even if the ball is given a hard kick.
A significant advantage of an inflatable ball of this type is that it can be collapsed to assume a highly compact state for storage and shipment. And unlike a conventional ball, it can be packaged in a small box or other container. The present invention seeks to impart the same advantage to a hula-hoop.